Current-induced breakdown of the quantum anomalous Hall effect

The quantum anomalous Hall effect (QAHE) realizes dissipationless longitudinal resistivity and quantized resistance without the need of an external magnetic field. However, when reducing device dimensions or increasing current density, abrupt breakdown state occurs with a relatively small critical current, limiting applications QAHE. We investigate mechanism this by studying multi-terminal devices identified that electric field created between opposing chiral edge states lies at origin. propose electric-field-driven percolation two-dimensional charge puddles in gapped surface compensated topological-insulator films is most likely cause breakdown.